PHYSICAL AND CHEMICAL-CHANGES IN DIFFERENT ZONES OF NORMAL AND PSE DRY-CURED HAM DURING PROCESSING

The changes of moisture, pH, NaCl, nitrate and nitrite in different zones of the ham during the process were evaluated in 15 normal and 15 PSE hams. No difference in pH was found between PSE and normal hams. When all the sampling times were analysed together, the PSE hams were found to contain more moisture and NaCl than normal hams in certain muscles. In most zones, pH increased during the process. The external zones showed a higher salt concentration at the beginning, but this trend reversed during aging owing to salt penetration from the drier external zones to the more humid inner zones. The total NaCl in the lean tissue of the hams increased after salting and remained constant after the resting phase. Nitrate diminished quickly during the resting period, especially in the external zones, whereas nitrite increased after the salting period and did not exceed 10 ppm at the end of the process. Dry cured ham is a nonhomogeneous product that undergoes a salting and dehydration process that determines the dynamics of the migration of the water, NaCl, nitrate and nitrite.